Peroxide vs. Non-peroxide Tooth Whitening
There are various methods and procedures (in-office bleaching, home kits, whitening strips, DIY remedies, etc.), but also different kinds of tooth whitening products available in the market. Most of the current methods can be split into two categories: those that use peroxide as the active ingredient and those that don’t. This article aims at shedding some light on the significant differences between all the options and clearing up some common misunderstandings.
There are two types of peroxide-based teeth whitening gels: hydrogen peroxide (for chair-side use) and carbamide peroxide (for home use).
When it comes to teeth whitening, hydrogen peroxide is the main and strongest active ingredient used by dentists worldwide. It breaks down into oxygen and water and it starts working right after applying it to the teeth, yielding dramatic results in less than an hour.
Teeth have micro-fine pores, making the enamel a semi-permable layer. When hydrogen peroxide decomposes, oxygen penetrates the enamel through these pores to reach the discolored molecules (residue from coffee, tobacco, foods, beverages, etc.) inside the tooth. This process is excellent in terms of whitening effect, but it has a significant adverse effect— tooth sensitivity. When the pores of the enamel are open, teeth become more susceptible to dehydration and demineralization, which leads to tooth sensitivity.
In the United States and many other countries dentists offer whitening treatments with hydrogen peroxide concentrations of up to 40%.
Carbamide peroxide, also called urea peroxide, is made from hydrogen peroxide. To make carbamide, a urea molecule is added to each hydrogen molecule to make the gel much more stable. It was designed for over-the-counter teeth whitening products since hydrogen peroxide tends to have a short shelf-life, especially in higher concentrations.
During the whitening process carbamide breaks down into hydrogen peroxide, but it takes about 30-60 minutes for that process to start. Since this type of whitening takes longer, it’s most suitable for home whitening treatment and perfect for touch-up pens and take-home kits.
There is a 3:1 relationship between these. In other words, 35% CP is equivalent to around 12% HP, 22% CP is equivalent to 7% HP and 16% CP is equivalent to 6% HP.
Because abuse or improper use of peroxide can have negative effects on the teeth, the European Commission limited the concentration of peroxide in cosmetic products in 2011. Thus, according to the current legislation non-dental professionals in Europe can use only up to 0.1% hydrogen peroxide (present or released) and dentists can use only up to 6% hydrogen peroxide (or its equivalent 16% carbamide peroxide).
Non-peroxide based whitening
Due to the new legislation on peroxide content in cosmetic products, ‘peroxide-free’ teeth whitening has experienced a remarkable growth over the last few years, also beyond EU borders. The most common active ingredients in non-peroxide based whitening products are sodium bicarbonate, commonly known as baking soda, and sodium percarbonate.
As a mild abrasive, sodium bicarbonate helps remove superficial stains from teeth. Also, it has a cleansing action by loosening food debris, it neutralizes the production of acid in the mouth and it prevents bacteria overgrowth. However, if not used in the correct proportion – especially with plain baking soda – it can eventually erode the enamel and lead to tooth decay.
Sodium percarbonate is a safe and environmentally-friendly agent that has not only cleansing and whitening, but also antibacterial properties. When it comes into contact with saliva it decomposes into natural soda ash and peroxide (oxygen and water), though products sold in the European Union do not release more than 0.1% hydrogen peroxide, in compliance with the EU Cosmetics Directive
Sodium percabonate is being increasingly used by dentists to bleach dead teeth from the inside out — a process also know as internal bleaching. With this technique, instead of applying the whitening agent on the surface of the teeth to penetrate to the areas where discoloration occurs, the gel goes right to the tooth’s interior, which is a highly sensitive area. As sodium percarbonate gives good results with very little to no side effects, it’s the ideal whitening agent for such purpose.
In terms of efficacy it’s important to understand that these products cannot remove deep discoloration inside the tooth, like peroxide does. Nonetheless and depending on the brand and the formula, they can achieve nice results, especially sodium percarbonate. As a matter of fact, Beaming White’s sodium percarbonate gels have been tested on their efficacy by independent testing bodies such as Eurofins and were found to give an average bleaching efficacy of 3.6 shades, with testers yielding up to 7 shades whiter after 1 single treatment.
As far as safety is concerned, non-peroxide based gels will typically not cause any tooth sensitivity or gum irritation, so they are ideal for people with sensitive teeth or for those who are afraid of using products containing peroxide.